High-speed mechanism for hand-controlled sheet metal working machinery



Nov. 10, 1959 w. ECKOLD 2,911,862

HIGH-SPEED MECHANISM FOR HAND-CONTROLLED SHEET METAL WORKING MACHINERY Filed Sept. 12, 1955 2 Sheets-Sheet 1 H44; 75,? fcxo; 0

Nov. 10, 1959 w. ECKOL 2,911,862

HIGH-SP MECHANISM FOR CONTROLLED s '1' METAL WORKING c INERY 2 Sheets-Sheet 2 Filed Sept. 12, 1955 l'm emon' 1 4491 75k c KOL 0 HIGH-SPEED MECHANISM FOR HAND-CON- TROLLED srmnr METAL WORKING MA- 'CHINERY Walter Eckold, St. Andreasberg, Oberharz, Germany Application September 12, 1955, Serial No. 533,817 Claims priority, application Germany September 13, 1954 4 Claims. (Cl. 78-61) The invention relates to high-speed mechanisms for hand-controlled sheet metal machinery of the type in which the blank sheet is gripped between press tools moving in opposite directions, as for example disclosed in prior Patent No. 2,699,079, issued January 11, 1955. The press tools are operated by pressure rams and clamp the blank on either side preparatory to the actual deforming operation. Each tool consists as a rule of one or more pairs or of an odd number of jaws working in conjunction with each other, which move in opposite directions when a certain operating pressure is reached, and which thus produce the deformation or elongation of the clamped blank.

In this operation, the deforming tools will, however, only be fully effective if contact is made with the blank over the entire surface of the tool, since only then can the blank be gripped with the thrust necessary for the operation.

An object of the invention is to reduce substantially tilting over of the press tool due to an eccentrically applied pressure. It consists in a non-rigid arrangement of the press tools, such that they will automatically bear on the blank over their entire surface, even if the pressure transmitted to them does not act accurately at the centre. For this purpose the press tool itself, which might e.g. consist of a hollow conical die, may be articulated, and would act together with a correspondingly shaped support on which the blank rests. In one embodiment of the invention, which is preferred, the pressure ram and deforming tool are connected by an articulated link consisting of two parts, an outer movable one carrying the press tool, and an inner one rigidly connected with the ram. These two parts are connected preferably by a resilient material such as rubber, which on release of the ram pressure will automatically return the parts, and hence the tools, to their initial central positions.

A suitable arrangement of such a link could consist of two flat metal rings held by a rubber ring in between which is vulcanized to both of them. The articulated link is seated on the inner part on a projection of reduced diameter; it is held in place by flanged edges of the metal rings, which are beaded into corresponding dovetailed or similar recesses of the parts to be connected by the link.

Two embodiments of the invention will now be described in greater detail with reference to the accompanying drawings each of which shows one embodiment and which Figure 1 shows the upper and lower tools with parts in section, and Figure 2 is a side elevation partly in section of a modified tool.

In the embodiment illustrated in Fig. 1, the press tools consist of a pair of jaws 1 attached to an upper ram 2; and similar jaws attached to a lower ram 3. The ram 3 and the press tool which consists of the jaws 1 are connected by an articulated link consisting of two parts: an outer movable part 4 which carries the pair of jaws United States Patent ice 1, and an inner part 5, which is rigidly connected with j the lower ram 3.

flat metal rings 8, which are held by a rubber ring 7 between and vulcanized to both rings which are seated on a projection 9 of the part 5. Flanges 10 of the metal rings 8 are beaded into dove-tailed recesses 11 in the parts 4 and 5. This forms a permanent connection between those parts, which, however, permits the jaws 1 to adjust themselves freely so as to bear fully on the flat surface of the blank.

In the embodiment illustrated in Fig. 2, the press tool consists of a cup 12, which due to spherical faces 13 on the cup and on a body 14 can move in all directions. The resilient connection between the cup 12 and the body 14 consists here similarly of a rubber ring 7, which is vulcanized in between two flat metal rings 8. The flanges of the metal rings are again beaded into recesses in the circumference of the body 14 and the cup 12.

The upper and lower rams 2 and 3 are relatively movable in the swaging and drawing too-l toward and away from each other and this results in a relative lateral movement of the jaws 1 either toward each other or away from each other as to each individual ram. This takes place when the jaws 1 contact the work and a pressure force is applied on the rams in a direction toward each other. The movement of the jaws 1 of each pair in its ram is governed by the desired work step to be carried out that is for swaging or drawing and the movement of the jaws is dependent upon the mounting in the jaw holder as for instance shown in said Patent No. 2,699,079.

Constructions according to the invention are applicable to all those conditions in whicha thrust which is not applied accurately in the centre would have an adverse effect on the operation, and in which an automatic adjustment of the press tools is desired.

I claim:

1. In a tool for deforming sheet metal in swaging and drawing machines having a ram provided with a plurality of jaws, a mounting for the jaws comprising a movable part having a projection with a curved surface, a second movable part adjacent the first-mentioned movable part and having a curved surface in contact with the curved surface of the first-mentioned movable part, and a rubber ring provided around the projection and between the two movable parts, said curved surfaces and rubber ring permitting adjustment of the jaws to bear fully on the sheet metal to be worked each movable part being provided with a metal ring disc each in contact on one side with its movable part and the other side in contact with the rubber ring.

2. In a tool for deforming sheet metal in swaging and drawing machines having a ram provided with a plurality of jaws, a mounting for the jaws comprising a movable part having a projection with a curved surface, a second movable part adjacent the first-mentioned movable part and having a curved surface in contact with the curved surface of the first-mentioned movable part, and a rubber ring provided around the projection and between the two movable parts, said curved surfaces and rubber ring permitting adjustment of the jaws to bear fully on the sheet metal to be worked each movable part being provided with a metal ring disc each in contact on one side with its movable part and the other side in contact with the rubber ring, and each peripheral edge of each metal ring having an angular bent part forming a flange with the flanges of both metal ring discs being projected in opposite directions to engage the respective movable parts.

3; In a tool for deforming sheet metal in swaging and drawing machines having a ram provided with a pair of jaws relatively movable laterally as to the longitudinal axis of the ram, a mounting for the jaws comprising an inner part on the ram and having a projection with a curved surface, an outer part having a curved surface in contact with the curved surface of the inner part, said jaw being mounted on the outer part, and a flexible ring provided around the projection and between the outer and inner parts, said curved surfaces and flexible ring permitting adjustment of the jaws to bear fully on the sheet metal to be worked.

4. In a tool according to claim 3 in which the outer part is cup-shaped with a concave outer surface and a convex inner surface with its curved surface in the center part of the convex surface, and the ring having a concave annular surface to conform with the convex inner surface of the outer part.

References Cited in the file of this patent UNITED STATES PATENTS Fitzgerald July 9, Lundgren et al. Sept. 30, Burnett May 12, Beard Dec. 12, Harris June 5, Greig Nov. 27, Moore Oct. 7, Scott Mar. 20, Wennberg Apr. 28, Swartz Sept. 29, Bode July 10, Herbenar Jan. 22,

FOREIGN PATENTS France Dec. 26, 

